How did they worship, what kind of ceremonies?
Again worship varied. There was individual prayer. There were community celebrations. There was worship and rituals within temples. Since the general populous could not go into the temples, there was no public worship in the temples. The major public worship ceremonies would be those where the god was carried out of the temple in a shrine and paraded around town for people to see and returned to the temple. Within temples an ordained/purified priesthood carried out the daily, monthly and seasonal rituals.